Valve



M. M'. DRAKE Dec. 31, 1935.

' VALVE Filed Feb. 5, 1932 2 She ets-Sheet 1 4; ATTORNEY Dec. 31, 1935.

M. M. DRAKE VALVE Filed Feb. 5, 1952 2 Sheets-Sheet 2 703mm P /0a M ICU/ew 1 4 1 ATTORNEY Patented Dec. 31, 1935 UNITED STATES PATENT orrlcsVALVE Application February 5, 1932, Serial No. 591,019

9 Claims.

This invention relates to valves in general and more especially tovacuum and relief valves for use with containers of volatile and highlyexpansible fluids or fuel oil and the like.

In practice heretofore, it has been customary to fit containers such astank vessels, tank cars and storage tanks generally with vents of somedescription so that the containers may be efficiently sealed against theadmission of the elements or foreign matter to prevent the contaminationof the contents of such containers.

This practice was especially important when the containers were used forcarrying fluids such as fuel oils, edible oils and other like fluidsthat become volatile and quickly expanded with a slight rise intemperature.

This practice was also important to protect the walls of the structurefrom collapse or rupture.

The goose neck open type vent was at one time extensively used but itwas not satisfactory since it did not prevent the escape of valuablegases due to the evaporation of the volatile contents of the containers.Combination vacuum and relief valves then came into use. The type mainlyused, especially in marine practice, was controlled by springs. Thisspring control valve likewise has not given the best of satisfaction. Ithas proven unreliable and expensive to maintain in proper working ordermainly on account of the corrosion which would readily set in unlessthey received constant and careful attention. Owing to the constructionof such spring loaded valves, they are furthermore difficult to open forexamination and overhauling and so are liable to be neglected.

More recently weight loaded valves have been tried in an attempt tosolve the difficulties encountered with the latter spring controlledvalves which attempts have been successful in part.

As an instance, when these combination vacuum and relief valves orvacuum and vent valves are used for service on oil tanks and especiallyon sea going oil tankers, they are subjected to many corrosiveinfluences, on the outside from the elements and on the inside from thecorrosive nature of the contents. The valves also are often required tofunction in the presence of highly explosive gases.

It is therefore desirable that these valves be made not only of adurable and reliable material that is corrosion resisting but also inthe interest of safety that these valves be made of a nonmagnetic andnon-sparking material.

Furthermore the weight loaded valves heretofore use have been heavy andcumbersome,

therefore expensive to manufacture and diflicult and expensive tohandle, and install.

In view of the foregoing, the present invention aims to provide animproved combination vacuum and relief valve composed of a suitablemetal comparatively light in weight, practically immune to corrosion,especially from the ordinary elements encountered at sea and theordinary gases of the contents to be carried. The following is a typicalformula for the kind of metal 10 suitable for the structure disclosedherein:

Per cent Total carbon 2.80 to 3.10 Manganese 2.25 to 3.00 PhosphorusUnder 0.30 Sulphur Under 0.12 Silicon 1.20 to 2.20 Nickel 12.50 to 14.00Copper 5.50 to 6.50 Chromium 0.75 to 1.25

It is still another object of the present invention to provide animproved combination vacuum and relief valve having a minimum number ofparts, essentially four in number and requiring a minimum amount ofmachine work thereby to reduce the cost of manufacture and raw materialto a minimum.

It is still another object of the present invention to provide animproved combination vacuum and relief valve which is comparativelyweather proof, simple to install, reliable in operation and readilyaccessible for inspection, cleaning and overhauling.

It is still another object of the present invention to provide animproved combination vacuum and relief valve of the weight loaded typeespecially adapted for sea going tankers in that they will automaticallyseat themselves and remain seated without difiiculty at the averageangle to the vertical that the ship might assume even at the averagehigh sea.

A special feature of the present invention also resides in the fact thatthe valve may readily adapt itself to standardization so that withslight changes in the diameter of the valve openings or weights the samecan be provided to accommodate the various pressures and various degreesof vacuum.

Still another feature of the invention is the equipment of the valves sothat they can be readily manipulated for grinding or removal.

These and other features, capabilities and advantages of the inventionwill appear from the subjointed detail description of specificembodiments thereof illustrated in the accompanying drawings in whichFigure 1 is a diagrammatic elevation of a tank arrangement on a vesselequipped with one embodiment of the present invention;

Fig. 2 is a longitudinal section of one embodiment of the combinationvacuum and relief valve constituting the main part of the presentinvention;

Fig. 3 is a plan View partly broken away and on a slightly smaller scalethan Fig. 2;

Fig. i is a transverse section on the line 4-5 of Fig. 2; on a scalesmaller than Fig. 2 but larger than Fig. 3;

Fig. 5 is a transverse section on the line 5-5 of Fig. 2; on a scalesimilar to that of Fig. 4;

Fig. 6 is a diagrammatic plan view of a portion of a sea going tankerequipped with another embodiment of the present invention;

Fig. '7 is a diagrammatic side elevation of the tank arrangementillustrated in Fig. 6;

Fig. 8 is a longitudinal section of the combination vacuum and reliefvalve used with the embodiment illustrated in Fig. 6;

Fig. 9 is a transverse section on the line 99 of Fig. 8; and

Fig. 10 is a section on the line l5lfi of Fig. 8, on a scale larger thanthat of Fig. 8.

The combination vacuum and relief valve constituting the embodimentillustrated in Figs. 2 to 5 inclusive is used independently one valve toa tank as a rule. The tanks I and 2 illustrated in Fig. l are equippedwith the ordinary hatch trunks 3 and 4 having'formed thereon the standpipes 5 and 5, at the upper end of which are secured the pressure andvacuum relief valves 1.

The pressure and vacuum relief valves '5, see Fig. 2, consistessentially of four parts to wit, an outer casing or body'B, a' vacuumvalve 9, a pressure valve I0 and'a cover l i. The casing or body 8 isprovided with an annular connection or con.- necting member I2internally screw threaded to engage the externally screw threadedportion of the stand pipe 5 or 6.

Above the connection I2, there is provided an annular fin E3 spaced fromthe casing I2 by the annular recess ML. Above the annular fin '53, thereis provide-d the annular skirt I5 extending downwardly over the outletsof the vacuum ports 5, I! and E3, the annular wall portion Q9 of thecasing '8 being disposed between the ports I5, ii and i3 and the fin l3.

In the present instance, the casing 8 has its upper main wall 2E!slightly smaller in diameter than the lower main wall 2 I. Nearthe-upper portion of the main wall 25, there is provided the annularoutwardly extending fin 22 which is disposed beneath and spaced from theannular skirt 23 extending down over the inlets to the pressure ports24, the main wall portion 253 extending up above the fin-ZZ and abovethe level of the lower end of the skirt 23. Above the skirt 23 the mainhousing 8 is closed by the cover I I which preferably sits on the gasket25 mounted on the upper end of the housing 8 to seal this opening whenthe cover I I is in place. a

The cover I I is preferably provided, see Fig. 3, with the ears 25 and21 disposed outside of the ears 28 and 29 formed on thecasing 8 toreceive'the pivot pin SE). The opposite end of the cover I! ispreferably provided with two parallel ears 3! and .32 to receive betweenthem the ear 33 of the casing 8, which ears SI, 32 and 33 when the coveris in closed position have alined openings to receive the anchor pin 35.

To form a support for the seat and guides of the vacuum valve 9, thebracket 35 is provided. The bracket 35, see particularly Fig. 5, has abottom wall 3'! forming the bottom of the chamber 38 in which the lowerportion of the vacuum valve 9 is slidably disposed and the bottom of theports Hi, I? and I8 extending therefrom. This bracket also has aplurality of vertical walls 35, 39, ii], it and GI, M which aresubstantially radial to the center of the casing 8 and are formed inpairs of walls 39 and 39 forming the side walls of the port I5, thewalls 40 and 40' forming the side walls of the port I! and the walls 4|and GI forming the side walls of the port E8.

The bracket 36 also has in the present instance three arcuate verticalwalls 42, 43 and 4 substantially concentric to the casing 8. The walls38 and 4% connect the extension 45 of the annular wall I9 with thearcuate wall 42, the walls 35 and ii connect the extension 46 of theannular wall I9 with the arcuate wall 45 and the walls fill and 5|connect the extension 47 of the annular wall I9 with the arcuate wall43. The skirt I5 is preferably reinforced by the vertical webs 458, 49and 50 which in the present instance are equally spaced from oneanother, the web 58 connecting the skirt I5 with the extension 45, theweb 49 connecting the skirt I5 with the extension 57 and the web 5!!connecting the skirt I5 with the extension 45.

The upper portions of the ports I6, I! and I8 are provided with theinclined roof wall members 5i which shut oif the ports I6, I! and I8from communication with the interior of the casing 8 above the bracket36.

The bracket 38, see Fig. 2, is provided with a central opening at theupper end of the chamber 38 and provided with an inclined valve seat 52to receive the inclined face 53 of the vacuum valve 9 in closed positionwhereby communication to the outside atmosphere from the interior of thecasing 8 through the chamber 38, ports I3, H and i8 and mouths of theskirt I5 is normally shut off or closed. The valves 9 and I0 arecharacterized by a valve head, a main body and an intervening neck. Themain body is provided primarily to form a weight to cause the valve toseat by the operation of gravity and the distribution of weight of thevalve between the head and main body is such as to bring the center ofgravity well below the valve head so that with the ordinary inclinedpositions of a sea going vessel at high seas, it will cause the valvehead to remain seated when the opening emergency is not present.

The valve 9 has as an instance a disc-shaped, cylindrical head 54 whichis connected to the Weight forming body 55 by the neck 55, the seatengaging face 53 being disposed adjacent to the neck 55. The weightforming body 55 preferably has an extended cylindrical outer surfacenormally concentric with the casing 8 and formed primarily to cooperatewith the vertical guiding fins 5?, 58 and 59 which in the presentinstance are disposed to extend inwardly from the middle of the walls32, 53 and 44 respectively.

The inner faces of these fins 57, 58 and 59 preferably aline or registerwith the innermost edge of the valve seat 52 so that the valve 9 may bemoved upwardly out of the bracket 36 through the valve seat 52. Thevalve head 54 preferably has an outer diameter considerably larger thanthat of the valve seat 52 and is preferably provided with an outercylindrical surface concentric with the casing 8 to cooperate with thevertically extending guides, three being provided in thepresent-instance, to wit 61 and 62, which extend inwardly from the wallportions 28 and 2| of the casing 8 and have inner arcuate faces whichare substantially concentric with the casing 8 to cooperate in part withthe cylindrical face of the head 54. The head 54 is preferably providedat its upper end with a lug 53 having an orifice 64 therein to beengaged by a hook or other instrument either for withdrawing the vacuumvalve 9 upwardly out of the casing 8 after the valve H) has been removedand of course the cover ll opened. The lug 63 is also provided for theengagement of a grinding tool by means of which the valve seat 52 andface 53 may be ground in the usual way.

The guides 68, Si and 62 preferably as shown extend up from the topwalls 5| of the ports l6, ll and I8 up to the annular flange 65extending inwardly from the wall portion 28 and terminating in alinementwith the inner faces of the guides 65, BI and 62. The upper inner edgeof this flange 55 is preferably inclined to form the valve seat 66 forthe pressure or relief valve In to engage the inclined face 61 of saidrelief valve-l6.

The valve In is provided with a head 68, a weight forming body 69 and anintervening neck 19 adjacent to the inclined face 61 of the head 68. Theweight forming body 69 is preferably provided with an extendedcylindrical outer surface concentric with the casing 8 and just clearingthe guides 68, 6| and 62 to be guided thereby in the vertical movementof the valve [0.

The lower end of the weight forming body 69 is preferably provided witha circular orifice H to serve as an additional clearance for the lug 63.

The head 58 has a diameter considerably greater than the diameter of theweight forming body E59 and also is provided with a cylindrical outersurface concentric with the casing 8 tocooperate with a plurality ofguiding fins, four being shown in the present instance to Wit, see Fig.3, the fins l2, l3, (4 and 15, the inner faces of which are preferablyconcentric with the casing 8 and formed to provide vertical guides forthe head 68.

The head 53 is also provided with a lug l6 having an opening 11 thereinto form a handle or accommodatea hook or other instrument either forremoving the valve It! or for grinding the same.

F From the foregoing, it will appear that when the cover l I is open thevalve 9 may first be moved into place along the guides 69, BI and 52until its weight forming body 55 slidably engages the guides El, 53 and59 and the inclined face 53 engages the seat 52, whereupon the valve IEmay be moved into place with the weight forming body 69 slidablyengaging the guides 68, El and 52 until the face 8'! of its head engagesthe seat .66 of the flange (i5, whereupon the cover may be closed andlocked in place by the pin 35 in the usual Way.

From the foregoing, it will appear that the interior of the tankequipped with this compound valve will communicate with the lower faceof the valve ii] to raise the same should the pressure therein exceedthe predetermined pressure to afford relief and in turn the outeratmosphere will cooperate with the lower face of the valve head 54 ofthe valve 9 to raise the same in case the atmospheric pressure exceedsthe interior pressure within the predetermined limits.

It will also be apparent that to meet the pressure requirements, thevalves 9 and I0 can easily be constructed to increase or decrease theweight thereof and similarly the areas of the valve ports may be variedwithout departing from the general construction of the valve and thusfacilitate 5 standardizing this type of valve for a great variety ofpressures and furthermore that even for a given equipment, the valvesmay be changed to meet a different pressure requirement by changing theweight of the valve members and valve 103 port areas without removing agiven equipment, which latter might become important when a tanker forinstance is going in one direction with one type of fluid having onepressure requirement and returning in the other direction with anot er15' type of fluid having another pressure requirement.

It is of course well known that while the average tanker is notinterchangeably used for fuel oils and edible oils, it may beinterchangeably used for crude oil and refined oil or crude oil, 201

refined oil and high test casing head gasoline.

These several main elements of the valve, to wit the casing 8, vacuumvalve 9, relief valve l8 and cover H and also the pins 39 and 35 in thepresent instance are preferably made of a cor- 25 rosion resisting metalwhich is in addition nonmagnetic and non-sparking so that the valveequipment will be substantially weather proof not only as to moisturebut also as to the salt water of the sea and in addition be safe withhighly ex- 30 plosive gases such as high test casing head gasoline.

It is also desirable that these several valve parts will becomparatively light in weight, easy to handle and manufacture and low incost. Ex- 35 cellent results have been obtained with the kind of metalwhich has already been developed and which is comparatively light inweight, practically immune to corrosion, non-magnetic and non-sparking.It will also be obvious from the 40' valves 9 and I9 and the clearanceformed above the same that in case of an emergency they will be free toeffectively open the valve members although in practice the change inpressures will ordinarily be gradual and it has been found that 15 "evenwhen loading or unloading a tank these valves will merely chatter ontheir seats while the pressure changes.

Preferably these valve casing are also provided with a frame screen suchfor instance as the 50 screen l2 secured in the connection E2 of thecasing 8 which is preferably composed of some corrosion resisting metalsuch as Monel metal or the like.

In the embodiment shown in Figs. 6 to 10 in- 5 clusive, an arrangementis shown which is used with the so-called inclosed type as distinguishedfrom the atmospheric type, although in the final analysis relief to andfrom atmosphere is also depended upon in this arrangement except that 60the opening to and from the atmosphere s remote from the tank andindividual valve members.

In Fig. 6, an arrangement of tanks 18, is, 88-, SI, 82 and 83 such as iscommon on a sea going tanker is shown in plan with the hatches 83, 85, 685, .87, 38 and 89. Each of the hatches is provided with a combinationvacuum and relief valve 98 such as illustrated in detail in Fig. 8.

The valves 98 of the hatches 84, 85, 86 and ii! are connected by thebranchway conduits 9!, 92, 93 and 94 to the main conduit 95. The valvesso of the hatches 88 and 89 are connected by the branchway conduits 96and 91 to the main conduit 98. The main conduits 95 and 98 are connectedto the upright conduits 99 and Hill extend- 75 ing up alongside of themast 1I 0I of the vessel and preferably terminating .in the hookedextensions I02 and I03, the mouths of which face downwardlyto protectthe same from the reception of rain, snow and the like. These extensionsand I00 arealso preferably provided with -flame screens preferablycomposed of some suitable corrosion resisting metal such for instance asMonel metal "or the like.

The valves 90 in the present instance are also composed of four mainelements, to wit the casing tea, the cover I05, the vacuum valve I06 andthe pressure or relief valve H31. The casing I04 in the present instancehas a cylindrical extension I08 preferably provided with an annularflange 09 to be connected to the conduit from the tank. The casing I00is also preferably provided with a laterally extending member H0provided with an annular flange H! to be connected to the conduitmembers communicating with the upright extensions 99 'or 500.

The casing I00 is also provided with a bracket II 2 having a verticallyextending arcuate wall portion H3, a lower annular flange portion II A,an upper annular portion II 5 forming a, chamber in communication withthe opening H6 formed in the conduit I08. The bracket H2 as shown inFig. 9 continues into the lateral walls In and IE3 of the casing I00 andforms with it the lateral wall for the chamber I I9 in communicationwith the opening H0.

The lower annular flange H2 preferably has an upper inner inclined valveseat I20 to receive the inclined face I2! of the vacuum valve I06.

The vacuum valve 05 consists essentially of a head E22, a weight formingbody I23 and an intervening neck lE- disposed adjacent to the inclinedface E2I of the head I22. The weight forming body 523 is preferablyprovided with an extended cylindrical surface concentric to the valvelet and slightly smaller in diameter than the diameter of the openingthrough the flange H4;

The chamber formed below the annular flange H4 of the casing I00 ispreferably provided with a plurality of vertically extending guides,there being in the present instance shown four such guides, to wit theguides I25, I20, I21 and I28, the inner faces of which are preferablyarcuate and concentric to the weight forming body I23 to facilitate thevertical slidability of the body I23 relative to such guides.

The head IE2 is preferably provided with a lug I29 having an orifice I30formed therein to serve as a handle or to receive a hook or otherinstrument to facilitate manipulating the valve I00 either to remove thesame or to grind the same.

The flange H5 is preferably provided with an upper annular innerinclined valve seat I3I to receive the inclined face I32 of the valveI01. The valve I91 consists essentially of a head I33, a weight formingbody I34 and an intervening neck I35 disposed adjacent to the inclinedface The weight forming body I as preferably has an extended outercylindrical surface concentric with the valve 501 and just clearing theguides formed in the casing H2 so that the valve I01 and especially itsbody H.3 3 may be guided by such guides, to wit the guides I 30, I31,I38 and E39 vertically extending in the chamber H9 and having arcuateinner faces concentric with the body I30. The head I22 "of the valve I00 .has

I34 of the valve I01 but also the head I22 of the valve I06 will be.guided by these guides I36, I31, I38 and I30.

The .head I33 of .the valve I01 is also provided with .an outercylindrical surface, the diameter of which is greater than the diameterof the body E34 but small enough to clear the guides formed in'thechamber disposed above the brack-' et H2, in the present instanceprovision being made for three of them, .to wit the guides I 40 equallyspaced from one another, only two being shown the third being .disposedin the part of the casing cut off by the section. These guides I 40 arealso provided with inner cylindrical faces concentric with the head I33to facilitate the vertical slidability of the same. The head I33 isprovided with a lug I II having an orifice I42 therein to serve as a'handle or abutment for a hook or other instrument used for removing thevalve I01 or for grinding the same. The upper end of the casing 104terminates in an annular shoulder M3 which "is provided with a coverI40, the annular flange of which engages the gasket I05 located betweenthe shoulder I43 and the cover W1. The annular flange of the cover M0 ispreferably provided with the bolts M6 engaging the shoulder I43 to lockthe cover I44 in place.

In order to afford additional clearance when desired for the vacuumvalve I00, the body portion 534 of the pressure valve I01 is preferablyprovided with a recess I4 1 disposed centrally in its lower end. v

To facilitate flushing the casing I 04 and cleaning the same from anyaccumulation of sediment and the like the lower end is generallyprovided with an opening I as to receive a screw threaded plug Hi0normally to close the same.

The valve illustrated in Figs. 8, 9 and 10 in its operation issubstantially identical to the valve illustrated in Figs. 2 to 5inclusive, the atmospheric pressure in the conduits leading to theuprights 90 "and acting upon the lower faces of the vacuum valves toraise the same should the pressure in the tanks drop below atmosphericpressure within certain limits. Likewise, the weight of the valves I01,together with the atmospheric pressure upon the upper facesof thesevalves is not suflicient to resist a predetermined gas pressure in thetanks, and hence, excessive pressure built up in the tanks is relievedby automatic raising or opening of these valves in response to thediiferential pressure.

The valves of this embodiment are preferably composed of light,non-corrosive, non-magnetic and non-sparking metal and for similarreasons it mayalso be desirable to produce the conduits equipped withthis embodiment of the same kind of metal.

It is of course obvious that the communication from the opening I I 6 ofthe conduit connection I08 to the opening I50 of the conduit connectionIII] will be exclusively established through the opening in the flangeH4 and through the chamber formed below the bracket H2 when atmosphericpressure exceeds the pressure in the tank within certain limits and thatin turn the communication from the opening H6 of the conduit connectionI03 to the opening I 50 of formed in the annular flange H and chamberformed above the same, and then to one side of the bracket H2 when thepressure in the tank exceeds atmospheric pressure within certain limits.

From the foregoing, it will appear that in the embodiment illustrated inFig. 2, the bracket 36 and annular flange @5 form between them a centralchamber which communicates with the vacuum sensitive chamber formedwitlnn the bracket 35 and also with the pressure sensitive chamberformed above the annular flange 65. This central chamber furthermore isin constant communication with the device to be protected, to wit thetank I or 2 through the connection iii.

In turn the embodiment illustrated in Fig. 8 is provided with a centralchamber in direct communication with the device to be protected by meansof the conduit member H6. This central chamber formed by the bracket H2also communicates with the vacuum sensitive chamber formed below thesame and with the pressure sensitive chamber formed above the same.

The vacuum and pressure sensitive chambers in both instances are ofcourse controlled by the gravity controlled valves there illustrated.

It is obvious that various changes and modifications may be made to thedetails of construction without departing from the general spirit of theinvention as set forth in the appended claims.

I claim:

1. A combination vacuum and relief valve having a casing, wall membersin said casing forming a pressure sensitive chamber, a vacuum sensitivechamber and a central chamber in communication with the device to beprotected and said pressure sensitive and vacuum sensitive chambers, avalve controlling the communication between said pressure sensitivechamber and said central chamber, a second valve controlling thecommunication between said vacuum sensitive chamber and said centralchamber, said valves being entirely confined within said casing, saidvalves having cylindrical heads larger than their communications andhaving narrower cylindrical depending body portions, the diameter of thehead of the vacuum sensitive valve and the diameter of the body of thepressure sensitive valve being the same, vertical guides in said casingto slidably engage the head of said pressure sensitive valve, verticalguides to slidably engage the body of the vacuum sensitive valve, andcommon vertical guides slidably to engage both the body of the pressuresensitive valve and the head of the vacuum sensitive valve.

2. A combination vacuum and relief valve having a casing, wall membersin said casing forming a pressure sensitive chamber, a vacuum sensitivechamber and a central chamber in communication with the device to beprotected and said pressure sensitive and vacuum sensitive chambers, avalve controlling the communication between said pressure sensitivechamber and said central chamber, a second valve controlling thecommunication between said vacuum sensitive chamber and said centralchamber, said valves being entirely confined within said casing, saidvalves having cylindrical heads larger than their communications andhaving narrower cylindrical depending body portions, the diameter of thehead of the vacuum sensitive valve and the diameter of the body of thepressure sensitive valve being the same, vertical guides in said casingto slidably engage the head of said pressure sensitive valve,verticalguides to slidably engage the body of the vacuum sensitive valve, andcommon vertical guides slidably to engage both the body of the pressuresensitive valve and the head of the 5 vacuum sensitive valve, saidvalves being coaxial to one another and so arranged that they may besuccessively removed past said guides without disassembling thestructure.

3. A combination vacuum and relief valve 10 having a casing, wallmembers in said casing forming a pressure sensitive chamber, a vacuumsensitive chamber and a central chamber in com munication with thedevice to be protected, said wall members having valve seats formeddirectly thereon between said central chamber and said vacuum sensitivechamber, and between said central chamber and pressure sensitivechambers, the valve seat for the vacuum sensitive chamber being disposedbelow the valve seat for the pressure sensitive chamber and in alinementtherewith and also of smaller diameter, valves cooperating with saidseats to control the communications from said central chamber to saidvacuum sensitive and pressure sensitive chambers, each valve having ahead larger than its valve seat and a downwardly hanging narrower weightforming body to locate the valve center of gravity below the valve seat,the weight forming body of the upper valve and the head of the lowervalve having substantially the same diameter to pass through the uppervalve seat and the diameter of the weight forming body of the lowervalve conforming to the diameter of the lower valve seat to passthrough, and separate guiding means for each valve for guiding eachvalve in non-tilting relation inall of its phases of operation.

4. A combination vacuum and relief valve having a casing, wall membersin said casing forming a pressure sensitive chamber, a vacuum sensitivechamber and a central chamber in communication with the device to beprotected, said wall members also forming seats between said centralchamber and said vacuum sensitive and pressure sensitive chambers, thevalve seat for the vacuum sensitive chamber being disposed below thevalve seat for the pressure sensitive chamber and in alinement therewithand also of smaller diameter, valves cooperating with said seats tocontrol the communications from said central chamber to said vacuumsensitive and pressure sensitive chambers, each valve having a headlarger than its valve seat and a depending narrower weight forming body,the weight forming body of the upper valve and the head of the lowervalve having substantially the same diameter to pass through the uppervalve seat and the diameter of the weight forming body of the lowervalve conforming to the diameter of the lower valve seat to pass throughit, and vertical guides in said casing to slidably engage the heads andweight forming bodies of the valves.

5. A combination vacuum and relief valve having a casing, wall membersin said casing forming a pressure sensitive chamber, a vacuum sensitivechamber and a central chamber in communication with the device to beprotected and said pressure sensitive and vacuum sensitive chambers, avalve controlling the communication between said pressure sensitivechamber and said central chamber, and a second valve controlling thecommunication between said vacuum sensitive chamber and said centralchamber, there being an annular series of openings between said pressuresensitive chamber and the atmos- VII phere, there being an annularseries of openings between said vacuum sensitive chamber and theatmosphere, two annular skirts, each annular skirt overhanging oneseries of annular openings and two annular fins, each annular fin beingdisposed below the opening to a skirt but spaced therefrom to form alateral mouth below its series of annular openings.

6. A combination vacuum and relief valve having a casing, wall membersin said casing forming a pressure sensitive chamber, a vacuum sensitivechamber and a central chamber, there being a lateral opening in saidcasing to afford communication from said central chamber to the deviceto be protected, there being a, second lateral opening in said casing toafford communication between said pressure sensitive and vacuumsensitive chambers to a conduit in communication with the atmosphere, a.valve seat for the communication between said central chamber and saidpressure sensitive chamber, a second valve seat for the communicationbetween said central chamber and said vacuum sensitive chamber, a valvecooperating withthe valve seat in said pressure sensitive chamber, and asecond valve cooperating with the valve seat in said vacuum sensitivechamber, there being an opening formed in the bottom of said casing tofacilitate flushing the same when desired.

7. A combination vacuum. and relief valve construction comprising a;plural-i'tvof casings; each casing having wall members forming apressure sensitive chamber, a vacuum sensitive chamber and a centralchamber; a pair of' conduits leading from opposite sides of each casing,each casing having lateral openings communicating respectively with theconduits, one of the openings in each casing establishing communicationfrom said central chamber through its. conduit'to the device to beprotected; the" other opening in each casing communicating with thepressure sensitive chamber and with the vacuum sensitive chamber, avalve seat formed in: the wall. structure of each casing to facilitatecommunication between the central chamber and the pressure sensitivechamber, a second valve seat formed inthe wall structure on each casingto facilitate communication between the central chamber: and the vacuumsensitive chamber, valves normally closing said seats, and a common pipecommunicating with the: atmosphere and with the last mentioned openingon eachcasing through one of said conduits.

8. A combination vacuum and relief valve having a casing; wall membersin said casing forming a pressure sensitive chamber and a centralchamber in communication with the device to be protected; said centralchamber communicating in opposite directions with the pressure sensitiveand vacuum sensitive chambers, a valve controlling the communicationbetween said pressure sensitive chamber and said central chamber, asecond valve controlling the communication between said vacuum sensitivechamber and said central chamber, said casing having valve. seats forthe valves, and vertical spaced guides formed as radial flanges in thewalls of said chambers, portions of said guides being common to bothvalves, said valves slidably engaging said guides to facilitate guidingthe latter into seating relation upon said seats and normallymaintaining the valves in non-tilting engagement with said verticalguides regardless of whether said valves are open, closed or operating.

9. A combination vacuum and relief valve hav ing a casing; wall portionsin said casing forming a pressure sensitive chamber, a vacuum sensitivechamber communicating with the atmosphere and a central chamber havingvalved communication with said pressure and vacuum sensitive chambers;there being a lateral opening in said casing to afford communicationfrom said central chamber to a device to be protected; there being asecond lateral opening in said casing communicating with said pressuresensitive chamber, a conduit communicating with said opening and latterchamber for discharging at a location remote from said casing, a valveseat for the communication between said central chamber and saidpressure sensitive chamber, a second valve seat for the communicationbetween said central chamber and said vacuum sensitive chamber, a valvecooperating with the valve seat in said pressure sensitive chamber, anda second valve cooperating with the valve seat in said vacuum sensitivechamber, said valves having cylindrical heads larger than theircommunications and having smaller depending body portions, the diameterof the head of the vacuum sensitive valve and the diameter of the bodyof the pressure sensitive valve being the same, vertical guides in saidcasing to slidably engage the body of the vacuum sensitive valve, andcommon vertical guides slidably to engage both the body of the pressuresensitive valve and the head of the vacuum sensitive valve.

MARCUS M. DRAKE.

